Аннотация: This article examines the evolution of state–religion relations in Eastern European countries in the post-socialist period (since 1989). The study aims to identify and typologize the models of interaction between the state and religious organizations that have emerged following the abandonment of state atheism. Through comparative legal and historical-institutional analysis, three dominant models are distinguished: (1) the “symphonia” model (Russia, Bulgaria, Romania), which recognizes the special role of a traditional confession in national life; (2) the concordat model (Poland), based on contractual relations between the state and the Church while preserving its autonomy; and (3) the liberal-secular model (the Czech Republic), which emphasizes strict state neutrality and confines religion to the private sphere. The article also addresses distinctive cases—Albania and Georgia—that illustrate alternative approaches to regulating religious pluralism. Despite shared initial conditions and the influence of European standards, the region has developed a divergent landscape of legal and political regimes, shaped by historical–cultural contexts, confessional composition, and national strategies of political legitimation. The study demonstrates that the transformation of the religious sphere in Eastern Europe remains multifaceted and continues to play a significant role in shaping public order and national identity in the 21st century.